Multi-constrained fast trajectory optimization of glide phase for hypersonic vehicle

In order to improve the efficiency and stability of the trajectory planning of glide phase for hypersonic cruise vehicle, this paper proposes an efficient trajectory optimization approach based on the theory of hierarchical planning. Firstly, the equations of motion and optimization for the vehicle are presented. Secondly, the algorithm generates a safe corridor according to the constraints of trajectory and quasi-equilibrium. Then a reference trajectory can be found in the safe corridor according to the constraints of terminal. The optimized trajectory can be achieved after optimizing the reference trajectory by the conjugate gradient method. Finally, the simulation about time-shortest trajectory is demonstrated, furthermore, the results of the simulation verify that the planned trajectory can satisfy all the flight demands of the glide phase and this method has the advantages of high efficiency and strong stability, which can satisfy requirements of online vehicle route planning.